# a = [1, 2, 3, 4]
# print(1 in a) # 1 在 a 里面是不是存在
# print(10 in a)
# print(1 not in a)# 1 在 a 里面是不是不存在
# print(10 not in a)#
#
# a = [1, 2, 3, 4]
# print(a.index(2))# 获取元素2的下标
# print(a.index(3))
# # print(a.index(10)) # 抛出异常

# a = [1, 2, 3, 4]
# # a.pop()
# # print(a)
#
# a.pop(1)
# print(a)

# a = ['aa', 'bb', 'aa', 'dd']
# a.remove('aa')
# print(a)

# a = [1, 2, 3, 4]
# b = [5, 6, 7, 8]
# c = b + a
# print(c)
# print(a)
# print(b)

# a.extend(b)
# # c = a.extends(b) # print(c) 结果为 None
# print(a)
# print(b)

a = [1, 2, 3, 4]
b = [5, 6, 7, 8]
a += b
print(a)
print(b)
